Multiple Access Technique (SATELLITE)

1. Consider a transponder with a 56 MHz bandwidth and an available single carrier C/No value of 97.5 dB Hz. Using a single channel per carrier – voice activated system (assume ∝ = 0.35) how many channels of QPSK modulated PCM can be sustained? Allow 3 dB loss for intermodulation and 10% for guard bands. Ignore companding.

For the same transponder, consider the case of two video carriers, each frequency modulated with an NTSC video signal. Calculate the video SNR. Allow 2.0 dB for intermodulation loss in C/No below the single carrier value.

Can someone tell me how to solve this question? What multiple access scheme should I use? Where can I find the formula for this question? Please help. I am clueless.